Appendix III
Answers to Chapter Review Questions
Chapter 1 Review: What Is Chemical Engineering?
1
2
3
Chemical engineering is a blend of:
A __Lab work and textbook study of chemicals
B X Chemistry, math, and mechanical engineering
C __Chemical reaction mechanisms and equipment re...
Chapter 1 Review: What Is Chemical Engineering?
1 Chemical engineering is a blend of:
A __Lab work and textbook study of chemicals
B X Chemistry, math, and mechanical engineering
C __Chemical reaction mechanisms and equipment reliability
D __Computers and equipment to make industrial chemicals
Answer: (b) Chemistry, math, and mechanical engineering. Though
chemical engineering includes the other answers, they are only minor
parts of a larger description.
2 Major differences between chemistry and chemical engineering include:
A __Consequences of safety and quality mistakes
B __Sophistication of process control
C __Environmental control and documentation
D __Dealing with impact of external variables
E X All of the above
Answer: (e) All of these factors are major differences.
3 A practical issue in large‐scale chemical operations not normally seen in
shorter‐term lab operations is:
A __Personnel turnover
B __Personnel protective equipment requirement
C X Corrosion
D __Size of offices for engineers versus chemists
Answer: (c) Corrosion issues are frequently not seen in short term lab-
oratory runs, especially if the lab work is done in glassware. Personnel
protective equipment specifications should be the same no matter the
scale of the work being done.
4 Issues that complicate large‐scale daily chemical plant operations to a much
greater degree than laboratory operations include all but which of the following
A __Weather conditions
B __Emergency shutdown and loss of utilities
C __Upstream and/or downstream process interactions
D X Price of company, suppliers, and customer stocks that change minute
by minute
Answer: (d) Weather needs to be considered because many large scale
chemical process operations are outside without building protection.
This subjects process equipment to wide fluctuations in temperature,
affecting to some degree any unit operation which is affected by tem-
perature or temperature differential (i.e., reactors, heat exchangers,
and distillation columns). Emergency shutdowns and loss of utilities
consequences are typically more severe, as well as process changes’
impact on directly connected processes. Though prices may be affected
by how well we do these things, it is not a direct concern.
5 A chemical engineering unit operation is one primarily concerned with
A __A chemical operation using single‐unit binary instructions
B X Physical changes within a chemical process system
C __Operations that perform at the same pace
D __An operation that does one thing at a time
Answer: (b) The concept of “unit operations” generally refers to pro-
cess operations which involve physical changes (separations). However,
in such unit operations as distillation, there are multiple unit opera-
tions involved.
Chapter 2 Review: Health and Safety
1 Procedures and protective equipment requirements for handling chemi-
cals include all but:
A X Expiration date on the shipping label
B __MSDS sheet information
C __Flammability and explosivity potential
D __Information on chemical interactions
Answer: (a) Though an expiration date is a useful piece of information
(especially in food and pharmaceutical packaging), it is not a key
requirement in this area. The other are far more important.
2 Start‐ups and shutdowns are the source of many safety and loss incidents due to:
A __Time pressures
B __Unanticipated operational and/or maintenance conditions
C __Lack of standard procedures for unusual situations
D X All of the above
Answer: (d) All of these items can and have contributed to significant
problems in plant startups.
, Appendix III 339
3 The “fire triangle” describes the necessary elements required to have a fire
or explosion. In addition to fuel and oxygen, what is the third item that
must be present?
A X Ignition source
B __Lightning
C __Loud noise
D __Shock wave
Answer: (a) An ignition source is required. Shock and lightning may be
causes but they are not a general description of what is required. They
are sub‐sets and examples of ignition sources.
4 The NFPA “diamond,” normally attached to shipping containers, indicates
all of the following except:
A __Degree of flammability hazard
B __Degree of health hazard
C X Name of chemical in the container
D __Degree of reactivity
Answer: (c) The point of this type of labeling is to give first responders
(most of whom will have no knowledge of chemistry) knowledge of the
type of material they are dealing with. The name of the chemical is use-
ful, but not important for emergency response with the exception of
immediate local responders with whom a local processing facility has
excellent close communication.
5 The lower explosive limit (LEL) and upper explosive limit (UEL)
tell us:
A X The range of flammability under some conditions
B __The range of flammability under all conditions
C __The upper and lower limits of the company’s tolerance for losses
D __The upper and lower limits of the amount of flammable material
pumped into a vessel
Answer: (a) UEL and LEL normally refer to limits at atmospheric
pressure and the material in pure form. Pressure and the presence of
other materials can change the UEL and LEL.
6 Autoignition temperature is the temperature at which:
A __The material loses its temper
B __A material automatically explodes
C X A material, within its explosive range, can ignite without an external
ignition source
D __Fire and hazard insurance rates automatically increase
Answer: (c) Autoignition does not mean a material will automatically
ignite or explode but it has the potential to do so without deliberate
ignition.
, 340 Appendix III
7 Toxicology studies tell us all but which of the following:
A __The difference between acute and long‐term exposure effects
B __Repeated dose toxicity
C __Areas of most concern for exposure
D X To what degree they are required and how much they cost
Answer: (d) These studies give us only data upon which to make
decisions.
8 An MSDS sheet tells us:
A __First aid measures
B __Physical characteristics
C __Chemical name and manufacturer or distributor
D X All of the above
Answer: (d) As required, an MSDS sheet must include all of this
information.
9 A HAZOP review asks all of these types of questions except:
A __Consequences of operating outside design conditions
B X What happens to the engineer who makes a bad design assumption
C __Safety impact of operating above design pressure conditions
D __Environmental impact of discharge of material not intended
Answer: (b) Though we might make some assumptions, this is not part
of the HAZOP review.
Chapter 3 Review: The Concept of Balances
1 The concept of balances in chemical engineering means that:
A __Mass is conserved
B __Energy is conserved
C __Fluid momentum is conserved
D X All of the above
Answer: (d) All aspects must balance.
2 If a mass balance around a tank or vessel does not “close” and instrumenta-
tion readings are accurate, then a possible cause is:
A __A reactor or tank is leaking
B __A valve or pump setting for material leaving the tank is incorrect
C __A valve or pump setting for material entering the tank is incorrect
D X Any of the above
Answer: (d) Any of these are possibilities. If a tank is leaking, there
should be some type of alarm system to alert that this is happening.
The same should be true of the other possible causes.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller StudyCenter1. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $18.49. You're not tied to anything after your purchase.
